# -*- coding: utf-8 -*- """ *************************************************************************** PointDistance.py --------------------- Date : August 2012 Copyright : (C) 2012 by Victor Olaya Email : volayaf at gmail dot com *************************************************************************** * * * This program is free software; you can redistribute it and/or modify * * it under the terms of the GNU General Public License as published by * * the Free Software Foundation; either version 2 of the License, or * * (at your option) any later version. * * * *************************************************************************** """ __author__ = 'Victor Olaya' __date__ = 'August 2012' __copyright__ = '(C) 2012, Victor Olaya' # This will get replaced with a git SHA1 when you do a git archive __revision__ = '$Format:%H$' import csv import math import codecs import cStringIO from qgis.core import * from sextante.core.GeoAlgorithm import GeoAlgorithm from sextante.core.QGisLayers import QGisLayers from sextante.parameters.ParameterNumber import ParameterNumber from sextante.parameters.ParameterVector import ParameterVector from sextante.parameters.ParameterSelection import ParameterSelection from sextante.parameters.ParameterTableField import ParameterTableField from sextante.outputs.OutputFile import OutputFile from sextante.algs.ftools import FToolsUtils as utils class PointDistance(GeoAlgorithm): INPUT_LAYER = "INPUT_LAYER" INPUT_FIELD = "INPUT_FIELD" TARGET_LAYER = "TARGET_LAYER" TARGET_FIELD = "TARGET_FIELD" MATRIX_TYPE = "MATRIX_TYPE" NEAREST_POINTS = "NEAREST_POINTS" DISTANCE_MATRIX = "DISTANCE_MATRIX" MAT_TYPES = ["Linear (N*k x 3) distance matrix", "Standard (N x T) distance matrix", "Summary distance matrix (mean, std. dev., min, max)" ] #=========================================================================== # def getIcon(self): # return QtGui.QIcon(os.path.dirname(__file__) + "/icons/matrix.png") #=========================================================================== def defineCharacteristics(self): self.name = "Distance matrix" self.group = "Vector analysis tools" self.addParameter(ParameterVector(self.INPUT_LAYER, "Input point layer", ParameterVector.VECTOR_TYPE_POINT)) self.addParameter(ParameterTableField(self.INPUT_FIELD, "Input unique ID field", self.INPUT_LAYER, ParameterTableField.DATA_TYPE_ANY)) self.addParameter(ParameterVector(self.TARGET_LAYER, "Target point layer", ParameterVector.VECTOR_TYPE_POINT)) self.addParameter(ParameterTableField(self.TARGET_FIELD, "Target unique ID field", self.TARGET_LAYER, ParameterTableField.DATA_TYPE_ANY)) self.addParameter(ParameterSelection(self.MATRIX_TYPE, "Output matrix type", self.MAT_TYPES, 0)) self.addParameter(ParameterNumber(self.NEAREST_POINTS, "Use only the nearest (k) target points", 0, 9999, 0)) self.addOutput(OutputFile(self.DISTANCE_MATRIX, "Distance matrix")) def processAlgorithm(self, progress): inLayer = QGisLayers.getObjectFromUri(self.getParameterValue(self.INPUT_LAYER)) inField = self.getParameterValue(self.INPUT_FIELD) targetLayer = QGisLayers.getObjectFromUri(self.getParameterValue(self.TARGET_LAYER)) targetField = self.getParameterValue(self.TARGET_FIELD) matType = self.getParameterValue(self.MATRIX_TYPE) nPoints = self.getParameterValue(self.NEAREST_POINTS) outputFile = self.getOutputValue(self.DISTANCE_MATRIX) if nPoints < 1: nPoints = len(QGisLayers.features(targetLayer)) # prepare CSV file writer csvFile = open(outputFile, "wb") self.writer = UnicodeWriter(csvFile) if matType == 0: # Linear distance matrix self.linearMatrix(inLayer, inField, targetLayer, targetField, matType, nPoints, progress) elif matType == 1: # Standard distance matrix self.regularMatrix(inLayer, inField, targetLayer, targetField, nPoints, progress) elif matType == 2: # Summary distance matrix self.linearMatrix(inLayer, inField, targetLayer, targetField, matType, nPoints, progress) csvFile.close() del self.writer def linearMatrix(self, inLayer, inField, targetLayer, targetField, matType, nPoints, progress): if matType == 0: self.writer.writerow(["InputID", "TargetID", "Distance"]) else: self.writer.writerow(["InputID", "MEAN", "STDDEV", "MIN", "MAX"]) index = utils.createSpatialIndex(targetLayer); inIdx = inLayer.fieldNameIndex(inField) inLayer.select([inIdx]) outIdx = targetLayer.fieldNameIndex(inField) outFeat = QgsFeature() inGeom = QgsGeometry() outGeom = QgsGeometry() distArea = QgsDistanceArea() features = QGisLayers.features(inLayer) current = 0 total = 100.0 / float(len(features)) for inFeat in features: inGeom = inFeat.geometry() inID = inFeat.attributes()[inIdx] featList = index.nearestNeighbor(inGeom.asPoint(), nPoints) distList = [] vari = 0.0 for i in featList: request = QgsFeatureRequest().setFilterFid(i) outFeat = targetLayer.getFeatures(request).next() outID = outFeat.attributes()[outIdx] outGeom = outFeat.geometry() dist = distArea.measureLine(inGeom.asPoint(), outGeom.asPoint()) if matType == 0: self.writer.writerow([unicode(inID), unicode(outID), unicode(dist)]) else: distList.append(float(dist)) if matType == 2: mean = sum(distList) / len(distList) for i in distList: vari += (i - mean) * (i - mean) vari = math.sqrt(vari / len(distList)) self.writer.writerow([unicode(inID), unicode(mean), unicode(vari), unicode(min(distList)), unicode(max(distList))]) current += 1 progress.setPercentage(int(current * total)) def regularMatrix(self, inLayer, inField, targetLayer, targetField, nPoints, progress): index = utils.createSpatialIndex(targetLayer) inIdx = inLayer.fieldNameIndex(inField) outIdx = targetLayer.fieldNameIndex(inField) outFeat = QgsFeature() inGeom = QgsGeometry() outGeom = QgsGeometry() distArea = QgsDistanceArea() first = True current = 0 features = QGisLayers.features(inLayer) total = 100.0 / float(len(features)) for inFeat in features: inGeom = inFeat.geometry() inID = inFeat.attributes()[inIdx] if first: featList = index.nearestNeighbor(inGeom.asPoint(), nPoints) first = False data = ["ID"] for i in featList: request = QgsFeatureRequest().setFilterFid(i) outFeat = targetLayer.getFeatures(request).next() data.append(unicode(outFeat.attributes[outIdx])) self.writer.writerow(data) data = [unicode(inID)] for i in featList: request = QgsFeatureRequest().setFilterFid(i) outFeat = targetLayer.getFeatures(request).next() outGeom = outFeat.geometry() dist = distArea.measureLine(inGeom.asPoint(), outGeom.asPoint()) data.append(unicode(float(dist))) self.writer.writerow(data) current += 1 progress.setPercentage(int(current * total)) class UnicodeWriter: def __init__(self, f, dialect=csv.excel, encoding="utf-8", **kwds): self.queue = cStringIO.StringIO() self.writer = csv.writer(self.queue, dialect=dialect, **kwds) self.stream = f self.encoder = codecs.getincrementalencoder(encoding)() def writerow(self, row): try: self.writer.writerow([s.encode("utf-8") for s in row]) except: self.writer.writerow(row) data = self.queue.getvalue() data = data.decode("utf-8") data = self.encoder.encode(data) self.stream.write(data) self.queue.truncate(0) def writerows(self, rows): for row in rows: self.writerow(row)